I guess I should mention that I have also a 2" return line for the water features...does that limit me to 73 gpm max rate?

No, you could move over 102 GPM through a 2" pipe, but it would take a great deal of energy to do so.

For 100gpm I would want 2 2" or 1 2 1/2" pipe.

Personally for what you are trying to achieve, I would look into a variable speed pump. I know there are more expensive but their dynamic properties could save you money and hassle in the long run.

Thanks racket! Would I be able to cut my fluid requirements if I went with a scupper instead of sheer decents? Nothing is set in stone on the type of water feature but I finished the gunite already and only have 2- 2" drain lines and 2 independent skimmers.

Does anyone know the water requirements of scuppers (made by tile and coping subs) vs.sheer decents. I went ahead and plumbed my water feature return line that is out of the gunite to 2 1/2" pipe...it was too late to change the 2" that was already in the ground.

Anyone else have any comments on my configuration? The water features (72" of sheer decent or scuppers and 4 deck jets) are individually valved with a 2hp Tristar pump.

Thanks!

Scott

Its about the same, It has to do with how much water you want on the wier, but I can't see it being that much different than a sheer descent.

Again, variable speed pumps are going to be the way to go here.

You are going to overpump or underpump, and besides this gets you out of buying a hayward pump.

Scott-

Good questions and you are obviously doing a lot of homework here as I did when I was building my pool.

The handcrafted scuppers can produce a nice water sheet for a large range of flows and will be more forgiving than sheer descents if water flow is low. Reason being, the scupperÂs weir angle and length can be adjusted to give the desired sheet. Lower angles or even negative angles (water pushing into the weir instead of falling off the weir) will require more flow to produce a nice sheet. Higher angles (water falling down a steeper and longer slope) will require less flow to produce a nice sheet.

The pump size should be determined by the water features that are selected. If you go with sheer descents and deck jets, the manufacturer will have a gpm rating. For a safety factor, assume worst-case flows for all water features added together then add 10% to that total. If you go with handcrafted scuppers go with a smaller pump and have them come back when you fire up the pump to tune the scuppers to your liking.

If you require more than 80-100 gpm for the water features, I would recommend a single speed pump that is sized appropriately for your water flow needs. Variable speed pumps are not that efficient over 80-100 gpm and if you plan to use the water features more than a couple hours a day, the energy savings will not justify the added cost of the variable speed pump.

However, if adjusting the power and sound of your water features is important to you, then a variable speed or 2 speed pump will give more flexibility depending on the mood you are trying to create. The variable speed pump, obviously, will allow more adjustments (more moods) than the 2 speed pump but at a cost.

If energy is not as important to you, then good old-fashioned valves at each water feature can be used to adjust water flow and set the mood. However, this does not create the same Âwow factor as pressing a button or flipping a switch to set the mood and obviously the use of valves drives energy consumption due to higher back pressure on the pump.

Just wanted to offer a few options and things to consider that may be important to your decision.

Hope this helps.

"However, this does not create the same Âwow factor as pressing a button or flipping a switch to set the mood and obviously the use of valves drives energy consumption due to higher back pressure on the pump."

A pump consumes more energy as it pumps more water, if you load the pump up it typically to a point will consume less "energy.

I know it defies logic, but compare a pump curve to its energy curve.

http://www.zoeller.com/zep/techbrief/JF1article.htm

If you look at the above link as the head decrease and the flow increases the energy consumption follows suit.

Every pump has a sweet spot, I just wish more pool pump mfr's put them in their curves like they used to.

"Higher angles (water falling down a steeper and longer slope) will require less flow to produce a nice sheet."

I wouldnt say one is more efficient than the other, a negative sloped weir will tend to funnel the water inward. The effect could also cause more turbulence to the water taking away the sheet effect. A flat, or positive slope will sheet more evenly, but positive slopes tend to stick closer to the wall therefore are undesirable. A flat weir seems to work to achieve the flattest most consistent effect.

Another thing I have noticed is that the longer the weir the more likely the sheet of water is to stick together. Same can be said on a sheer descent If you have a drop over 2-3 feet I would plan on using a 6" model.

racket - good point on the valving used to find the pumps most efficient sweet spot on the speed-torque curve. Throttle valves are great for finding this sweet spot and usually best overall sound as well.

The downside of throttle valves of course is overdoing the valving and driving power up and flow down.

Remember you can find that sweet spot throttling the valves while there is a clamp-on amprobe on the pump wires looking for and dialing into the lowest amp draw.

"Remember you can find that sweet spot throttling the valves while there is a clamp-on amprobe on the pump wires looking for and dialing into the lowest amp draw."

You can, but you are really are not going to see that large of a difference on a residential fractional HP motor.